There really is no such thing as a standard column size, it depends on what you want to store in that column.
For example take a password column. It depends on how you configure the site. Are you storing the password using SHA1 encryption? If so, set the column length to 40. An SHA1 string will always be 40 characters. But if not, there are other things to take into consideration:
are you forcing a certain password length? some site require the password be between 7 and 15 characters. In this case the length would be 15. if you not setting a maximum length, you'll want to make sure the password column can take the password that is entered so probably 50 to 100 characters.
The lengths in the user registration pack could be used as a starting point, but i wouldn't use them as a standard.